Power systems such as large internal combustion engines, for example, burn hydrocarbon-based fuels or similar fuel sources to convert the chemical energy therein to mechanical energy for powering an associated machine or application. Combustion of the hydrocarbon fuel may release or create several byproducts or emissions, such as nitrogen oxides (NOX), carbon monoxides and carbon dioxides (CO and CO2), and particulate matter. The quantity of some of these emissions that may be released to the environment may be subject to government regulations and environmental laws. Accordingly, manufacturers of such power systems may equip the system with an associated aftertreatment system to treat the emissions before they are discharged to the environment.
The aftertreatment system can be disposed in the exhaust channel of the power system and may include a unit or module through which the exhaust gasses may pass. The module may include one or more aftertreatment bricks that can change, chemically or physically, the composition of the exhaust gasses that encounter the bricks. Examples of aftertreatment bricks include catalysts that chemically alter the exhaust gasses and filters that can trap specific components of the exhaust gasses. In some embodiments, the aftertreatment brick may be permanently fixed to the module, such as by welding or the like. However, some types of aftertreatment bricks may become depleted or deactivated after a period of use, or may become damaged due to the conditions in which they are used, and require replacement. Accordingly, in some aftertreatment systems the aftertreatment bricks may be removable.
Some aftertreatment systems may use an array of catalytic bricks positioned adjacent one another to handle the desired volume of exhaust gas. For example, U.S. Pat. No. 5,409,670 (the '670 patent) discloses a selective catalytic reduction system having multiple pairs of catalytic members arranged in series. The '670 patent describes flanges attached to a mid-portion of each catalytic member that are sandwiched between a clamping plate and a sealing surface of an internal frame. While this arrangement attempts to reduce exhaust leakage between the catalytic member and the internal frame, it requires careful positioning of the catalytic member to ensure that the flange is located for proper clamping. Additionally, the system described in the '670 patent introduces potential leak paths between adjacent catalytic members.